1. Field of the Invention
The present invention relates to a ratchet wrench and, more particularly, to a reversible ratchet wrench that co-operates with a socket to operate a workpiece (such as a nut and the like) in two opposite directions.
2. Description of the Related Art
A conventional reversible ratchet wrench in accordance with the prior art shown in FIG. 7 comprises a drive shank 60 having an end portion provided with a support base 61 which has a receiving chamber 62, a receiving space 63, a through hole 631 and a positioning recess 632, a ratchet wheel 80 mounted in the receiving chamber 62 of the support base 61 and having an outer wall provided with a plurality of ratchet teeth 81, a pawl member 70 mounted in the receiving space 63 of the support base 61 and having a first side provided with a toothed engaging face 72 meshing with the ratchet teeth 81 of the ratchet wheel 80 and a second side provided with a triangular protrusion 71 which has two opposite oblique faces 73, a positioning ball 65 mounted in the positioning recess 632 of the support base 61 and abutting one of the two oblique faces 73 of the protrusion 71 of the pawl member 70, an elastic member 64 mounted in the positioning recess 632 of the support base 61 and biased between the support base 61 of the drive shank 60 and the positioning ball 65 to push the positioning ball 65 toward the protrusion 71 of the pawl member 70, a control shaft 74 extending through the through hole 631 of the support base 61 and inserted into the pawl member 70 to rotate and move the pawl member 70 relative to the positioning ball 65, a control lever 75 mounted on the control shaft 74 and located outside of the support base 61 of the drive shank 60 to drive the control shaft 74 to move the pawl member 70, and a cover 90 mounted on the support base 61 of the drive shank 60 to cover the ratchet wheel 80 and the pawl member 70. The cover 90 is combined with the support base 61 of the drive shank 60 by two locking bolts 93. The cover 90 is provided with a first limit hole 91 to limit the ratchet wheel 80 and a second limit hole 92 to limit the pawl member 70. The support base 61 of the drive shank 60 has a bottom provided with a limit bore 621 to limit the ratchet wheel 80. The ratchet wheel 80 has a side provided with a square drive stud 82 extending through and protruding outwardly from the first limit hole 91 of the cover 90 for mounting a socket to operate a workpiece, such as a nut and the like. Thus, a user can drive the control lever 75 to drive the control shaft 74 which drives the pawl member 70 to move relative to the positioning ball 65, so that the positioning ball 65 abuts one of the two oblique faces 73 of the protrusion 71 of the pawl member 70 so as to change the operation direction of the ratchet wheel 80. However, the user has to drive the control lever 75 to change the operation direction of the ratchet wheel 80, thereby causing inconvenience to the user.